The present invention relates generally to aeronautical vehicle systems, and more particularly, to a method and system for tactile cueing a vehicle operator as to a control inceptor position in response to vehicle states.
In an aeronautical vehicle, such as a helicopter, a vehicle operator uses control inceptors to control the vehicle. With traditional aircraft, the vehicle operator must continuously adjust the control inceptors positioning to maintain desired vehicle states, such as vertical velocity, airspeed, and others known in the art.
The control inceptors may be part of an active control inceptor system, which emulates mechanical components such as springs and friction clutches that are actuated by an electric motor or other actuation device known in the art. The actuation device is typically controlled via an active controller, to provide tactile cues to the vehicle operator. The tactile cues consist of varying tension on a control inceptor, such that the vehicle operator perceives that there is spring tension or friction load on the control inceptor.
For example purposes only, vertical velocity and vertical position or altitude control is described below. The vehicle operator adjusts a vertical control inceptor, hereinafter referred to as a control inceptor, to maintain a desired altitude or vertical velocity. Of course, similar control is used for longitudinal, lateral or directional control of an aeronautical vehicle.
Generally, by adjusting the control inceptor in an upward direction causes a collective blade pitch to increase, thus causing the vehicle to climb. Alternatively, by adjusting the vertical controller in a downward direction causes the collective blade pitch to decrease, thus causing the vehicle to descend. The control inceptor position required to maintain a constant vertical velocity or constant altitude is a function of many factors such as vehicle velocity, acceleration, and atmospheric conditions.
Advanced vehicle control systems currently exist in the art for maintaining a specific vehicle state. For example, a vehicle may have an control system capable of maintaining, one of two vehicle states, either a constant vertical velocity or a constant altitude. The vehicle operator has an option of commanding the vehicle control system to maintain one vehicle state or the other, but not both concurrently. In order to transition between vehicle states the vehicle operator must perform one or both functions manually, or perform internal vehicle tasks, described in more detail below.
Referring now to FIG. 1, a traditional tactile cueing model diagram including a tactile cue representation with a dual spring constant and detent for a single vehicle state is shown. Traditionally, an control inceptor system controller defines parameters of the tactile cue representation such that first slopes 1, of curve 2, have a first spring constant and a second slope 3, has a second spring constant. The second slope 3 is associated with a detent 4 that is relatively higher in slope than the first slopes 1. The detent 4 has upper and lower detent limits 5 corresponding to slope changes between the first slopes 1 and the second slope 3. A detent center position 6, or zero velocity position xcex4c{dot over (h)}=0, is commanded by a flight controller. For instance command of the detent position 6 can be continuously calculated by the flight controller as a position of the control inceptor, which corresponds to a constant altitude mode. When there is no force exerted on the control inceptor, by the vehicle operator, the control inceptor is adjusted by the flight controller to the detent position 6, sometimes referred to as a neutral position, and the vehicle maintains a constant altitude vehicle state. In order for a vehicle operator to command the vehicle to operate in a vehicle state other than constant altitude the vehicle operator needs to maintain a constant force on the control inceptor, thus maintaining the control inceptor at a position other than the position to maintain constant altitude.
Additionally, when the vehicle operator switches between vehicle states or vehicle operating modes or has a desire to maintain a different constant vehicle state, the vehicle operator is mentally and physically focusing on monitoring vehicle performance, turning a dial, flipping a switch, or performing some other internal vehicle actuation operation known in the art. The vehicle operator is therefore deterred from focusing on activity external to the vehicle, as in normal manual vehicle operation. The more internal vehicle tasks to perform, the higher a vehicle operator workload, and thus the higher the probability of a vehicle collision occurring and the fewer other tasks the vehicle operator can complete.
Furthermore, an aeronautical vehicle cockpit contains numerous vehicle actuators and operational controls including switches, dials, levers, controllers, monitors, and other actuators known in the art. The more actuators and operational controls, the more confusion during vehicle operation and the more costly the development and testing of a vehicle.
Consequently, a desire exists to provide a vehicle tactile cueing system that is capable of maintaining multiple vehicle states such as constant vertical velocity and constant altitude while minimizing vehicle operator workload and operating complexity. Moreover, the vehicle tactile cueing system should not increase but rather decrease the quantity of actuators and operation controls while increasing vehicle-handling qualities.
Also, it is desirable that a vehicle tactile cueing system operate in conjunction with existing vehicle control systems. For an aeronautical vehicle, relationships between a control inceptor position and corresponding vehicle response are control characteristics of the vehicle, which are carefully designed. Altering vehicle response characteristic can result in time consuming and costly testing of a vehicle and re-training of vehicle operators. Thus, a newly introduced vehicle tactile cueing system should not significantly alter this relationship.
The present invention provides a method and system for tactile cueing a vehicle operator as to control inceptor position for multiple vehicle states. A split detent tactile cueing vehicle control system for a vehicle is provided including an active control inceptor system. The active system includes a control inceptor having a plurality of positions and a position sensor that generates a control inceptor position signal. The system also includes a plurality of vehicle performance sensors that generate a plurality of vehicle performance signals. A flight controller is electrically coupled to the position sensor and the plurality of vehicle performance sensors, and generates a control inceptor actuation signal by applying a tactile cueing model and in response to the position signal and the plurality of vehicle performance signals. A method of performing the same is also provided.
The present invention has several advantages over existing tactical cueing systems. One advantage of the present invention is that it is capable of providing a vehicle operator tactile cues indicating control inceptor positions for more than one vehicle state including constant velocity and constant position.
Another advantage of the present invention is that it provides increased vehicle handling qualities with decreased vehicle operating complexity. Thus, the split detent tactile cueing vehicle control system decreases vehicle operator workload by decreasing the time the operator must spend performing in-vehicle tasks and increases the amount of time the vehicle operator focuses on activity outside the vehicle.
Furthermore, in combination with the aforementioned, the present invention provides a vehicle operator with operational ability to switch between vehicle states without any associated deterrences or distractions that are common in traditional tactile cueing vehicle control systems.
Moreover, the present invention is capable of operating in conjunction with existing vehicle systems and providing tactile cues to a vehicle operator via the control inceptor without altering existing relationships between control inceptor positions and corresponding vehicle responses.